Welcome Guest - Sign Up today
Welcome Guest - Sign Up today


No announcement yet.

1988 Yamaha pro50 randomly dies at WOT

  • Filter
  • Time
  • Show
Clear All
new posts

  • 1988 Yamaha pro50 randomly dies at WOT

    Hey everyone,

    I'm very new to the forums here but I have a problem with my motor that has me stumped. I bought a 1988 Yamaha Pro50 back in April and it has ran great untill this weekend. On Saturday I was out fishing and ran about a mile and all of a sudden it started to lose power and run real rough. So we fished a while and then went to go home and it had no power. It started fine but would create more that 2500 RPMs. But the it picked back up for a few minutes and then died. And wouldn't restart. So I came home and checked out the carbs and they are spotless. So I looked at the plugs and thought they looked a little fouled ( they were new in April) replaced them again and took the boat back out. It started and ran great for about a mile and a half then just died at WOT and wouldn't start for about five minutes but then started up and ran fine the rest of the way back to the ramp.

    Now I've checked compression and have 90 psi on all three cylinders. Have spark at all plugs. The carbs are clean and I have a new fuel hose and blub.

    Any thoughts on why it would act like that before I just randomly start throwing money at it chasing this problem?

    Thank you and I appreciate any and all input.


  • #2
    Check your fuel pump for a bad diaphragm.....


    • #3
      Thank you for responding. That is one thing I havent looked at yet. I will dig into it tonight and let you know how it turns out!

      Thanks again!!!


      • #4
        Check the coil


        • #5
          Hey guys,

          So last night to took the fuel pump apart and it looked good, I think by looking at it, it had to be replaced when the marine dealer tuned up the motor before i bought it as it looked new. Then i tested the coils with my ohm meter and couldn't get a reading across the secondary winding on coils one and two. But i could on the number 3 coil so i went ahead and bit the bullet and ordered two new coils. Thanks for the responses and if anyone has any more in case this doesn't fix the problem i would appreciate it.



          • #6
            Couple ideas, check and make sure primer bulb pumps up and stays firm, also check fuel line especially at tank nipple is tight and not sucking air. Let us know if coils fixed it.


            • #7
              Sign up today
              Hey guys, just an update. I am still waiting on parts to come in. will hopefully get out and run it on friday.